Breast cancer is the most common female malignancy and the leading cause of cancer-related death among women. The 2009 cancer statistics estimated that 181,000 new cases of invasive breast cancer were diagnosed that year and would result in 46,300 new deaths. In North America, breast cancer accounts for about 27% of all female cancers and 15% -20% of all female cancer mortalities. While advancement in the diagnosis and treatment of breast cancer has prolonged patient survival, alternative therapeutic agents for treatment of breast cancer are needed.
Protein kinase C-iota (PKC-ι), an atypical protein kinase C isozyme, plays an essential role in the growth, proliferation and survival of many types of cancer cells. PKC-ι has been shown to promote cell survival in ovarian cancer, non-small cell lung cancer and prostate cancer. However, PKC-ι has not previously been reported to play any role in breast cancer. It also remains unknown whether agents that inhibit PKC-ι activity would have any effect on the treatment of breast cancer.